Sheet-glass-surfacing table



June 3, 41930. w. H,4 PowLEssoN 1,761,746

SHEETl GLASS SURFACING TABLE Y I Filed J'an. 10, 1927 E n.. :-l..

attenua;

. gnou/Wo@ l/l'am h. Pow/essen Patented June 3, 1930 UNITED STA ,ES PATENT OFFICE.

WILLIAM H. POWLESSON, OF TOLEDO, OHIO, ASSIGrNORy T LIBBEY-OWNS GLASS COM- PANY, OF TOLEDO, OI-IIO, A CORPORATION OF OHIO `SHEET#amiss.sURFAcING TABLE Application filed yJanuary 10, 1927. Serial No. 160,160.

This invention relates 'broadlyV to sheet glass surfacing apparatus 'and has more particular reference to atable adapted to support the sheet during the surfacing opera-v "Lions-zv l I" In Ythe manufacture of plate glass, a blank is ground and polished uponbot-h sides to remove any Waves or surface distortions so thata clearer,A true `vision can be had when looking-therethrough. To do this, it is necessary tol support the plate glass blank during the surfacing operations in a manner that the opposite surfaces of the sheet will, after they have been ground and polished, be Ialmost absolutely parallel to each other which means that the sheet must be of uniform thickness throughout.

It is an Aaim of the present invention to provide a table having a sheet glass receiving recess therein for supporting the sheet '-during the grinding or polishingoperations in a manner that both sides of the sheet can be ground and polished to produce an absolutely uniform sheet of plate glass.

Another object of the invention is to provide a table of the above character wherein the plate glass blank can be freely supported during the surfacing operations, the said sheet being placed within a recess formed in the supporting table, and includes a protective pad interposed between the bottom of the recess and the sheet of glass being surfaced.

A further object of the invention is to provide a table of the above character having a recess for receiving a sheet of glass during the surfacing thereof and including a supporting pad resting upon the bottom of the recess, and a protective pad interposed betaken in connection with the'accompanying drawings. Y 1 Y In the drawings forming a part of thisap#V plication and wherein like numerals are'employed to designatev like parts throughout the same, v 5 'j Fig. lis a central vertical section' through an improved formv of supporting table .con-y structed in accordance with the present invention. y 1

Fig. 2 is a fragmentary section through a portion of the table, and

Fig. 3 is a top plan view of the table. j l* f In the drawings, the sheet supporting table, designated in its entirety by the numeral 5,-is mounted at the upper end of a vertical column 6 whichy freely rotates in bearings? within the frame work 8f lThe table is preferablysupported upon suitableroller bearings 9 and rotated by means of a large bevelled gear l0 secured to column 6 and driven through a bevelled pinion 11 keyedto the drive shaft 12, said shaft being rotated from any suitablefsource of power suchy as an electric motor orA the like. y

The table 5 has associated therewith aseries of preferably four segmentsor plates .13 ea'ch being adjustable through means of a screwarrangement 14. A stud 15 is provided with-a head 16 yadapted to run in the guide,-v way 17to prevent accidental displacement of the plates 13 when in use.

Secured to the upper surface of each of the segments or plates 13 adjacent toaand conformingwith the outer curved edge thereof is an arcuately curved strip of metal 18.which forms a backing for the similarly Vcurved wooden stripv19. Extending between the opposite ends of the curved wooden strip1r9 is a straight wooden strip 20 also secured to the plate '-orksegment 13. -This arrangement of the strips 19 and 20 lprovides 'a recess in the top of each plate or segment 13 and arranged within each of these recesses is a loosely/laid pad 21preferably of cork, although it'may obviously, be Yof felt or similar cushioning material. The pad 2l is adaptedto freely support a glass plate 22 and these plates constitute improved tool-supporting surfaces as has been ,clearly set forth andclaimd inthe copending application of Thomas J. Leyland iled J an. 10, 1927, Serial No. 160,060.

The four plates or segments 13 dene` a recess 28 Within which the glass sheet 211 may be positioned during the surfacing operations and this recessmay be slightlylarger than the sheetofv glass being surfacedji'f desired so thatthe said sheet be free'to move Within said recess during the grinding and polishingoperations. Y The undersurface of each plate or segment 13 is preferably. pro-l vided With a recess Within Which is disposed a felt Wiper 25 which Will prevent-*the abrasive fedY onto the glassfsheet from iinding its Way under the said plates. Y

y In orderfthat the V.surfaces ofthe sheetwill be parallel to each other, the bottom ofthe recess, 23 isso vorIrned ,thatit- Will produce a c mastersurfacewhich.will be reproduced upon thefplateof glass being ground.r j To prevent injury'to the underside oi'lthe sheetvvhile withinhe recess, the. said sheet is loosely' laid upon ,ad-,composition pad 26 which is. pret egrablycork, and an asbestosrpad 27 is interposed between thecork pad 26 and the bot# torn.,oflrecess23.A The asbestos pad is not in anyway cemented or fastened Within thev recess butfisplacedloosely therein and the cork. padisalso loosely laid upon-the asy bestospadso thatlboth, of said pads Will be 2; L" o i y 1,761,746

ing upon said table, and'acushioning padv supported upon said asbestos pad and adapted to receive thereon the glass sheet to beV l Worked upon. Y

= 3. In sheet glass surfacing apparatus, a

glass supportingtable,l andv a plurality of superimposed padscarried Ysaid table and adapted to support thereon kthe glass sheet to be surfaced, the bottom pad being formed of asbestos .and thetoppad-of asoftermay terial. y Y

4. In vsheet glass apparatus, a glass supporting table having a recess in its upper surface, and apluralityofpads loosely arranged Within saidrec'ess in superimposed'relation,

and being freely. movable independentlyfof one anothenthe glass sheet to be surfaced vbe- -V ingalso received'within said recess and resting upon/the up'permost pad, the bottom/padbeing formedof asbestosand the Vuppermost; pad'ofcork. Y Y Y 1 Y Signed at, TOledQ, m the Colmtgy "of Lucas and State; OfYOhOr this day Q fjdanuary, A

WILLI/AM POWLESS-QN.,

ablelheat-is generated andthe asbestos @pad Y prevents.. this heat from escapingthrough the table. yThegcork pad 27 isinterposedbetween; :the glass sheet and asbestos fpadin' order to protect saidsheet as'corkis not as hard. andgconsequently lnot as detrimental to the glass as .would be the asbestos ,pady did it contact` directly therewith.

Itis ,to loeunderstoodv that the vform ofthej no A inventionfherewith,y shown and describedis f y tobe ftak'enas .thefpreferred embodiment of the, same, and that kvarious;changes finl the shape, sizeand arrangementof parts may be resorted, to ,Without departing from the Vspirit 1.1`In sheet zgldassgsurfacing. apparatus, a

ofthe .invention or 4thecscope Iofthe sub-V y glassgsupporting table, yand gan abestos'k pad carried by said. table and adapted to support' the sheetto-:be surfaced. f l

2.,A In-,Qsheet glass: Vsurfacing apparatus, a 

